This invention relates to the packaging of clear-binders and a composition to prepare it. Clear-binders, also known as synthetic binders or transparent binders or synthetic clear bitumens are well known materials used in road building and industrial applications. They are bitumen-like products and are used likewise for the production of concrete mix, or paving mix, or industrial products, except for the color. While bitumens are black in nature and confer, after mixing with aggregates, a black color to the pavements, clear-binders are more or less transparent and enable for colorless or colored pavements or other applications with the use, or not, of pigments or dyes. Any color can be used for the production of colored mixes. A red color pavement for example, is a common sight.
Clear-binders are used in the same way as bitumens. In the main application, which is for pavement mixes, they are mixed with aggregates using the same installations as those using bitumens, that is bitumen concrete mixing plants or asphalt mixing plants. Additionally however, colored mixes require special care for ensuring consistent color for a given project. In this respect, clear-binders should not be contaminated with normal bitumen, as this would darken the produced mixes by conferring its black color. It is therefore normal practice for bitumen concrete mixing plants to thoroughly flush and clean the whole system, that includes dryer, pugmill, tanks, pipes, pumps, etc, when production of colored mixed follows that of normal black mix.
Flushing of bitumen concrete mixing plant consists in running the plant by mixing hot aggregates with the content of lines and pumps of binder until the final product is clean and free from asphalt or other color contaminating agents. This process may consume up to several tons of material that is ultimately dumped because it does not meet any of the usual material specifications. Bitumen concrete mixing plants that regularly produce colorless or colored pavements may or may not have a separate system to handle clear-binders.
The sensitivity to contamination of clear-binders by normal asphalt is a severe limiting factor to their use and application. Flushing or dedicated facilities incur cost, time and wastage. This all adds to the final cost of colorless or colored pavements.
Compared with normal bitumens, clear-binders are used in relatively small quantities by the paving industry. Due to the specific nature and relatively higher price of clear-binders, containers for transporting them must be dedicated ones and cannot be used for other purposes. As such, clear-binders are most often packed in clean steel drums.
Obviously, the cost for maintaining dedicated containers increases the overall cost of the material and does not prevent from thorough flushing of the installation before use. Drums on the other hand need be heated before transfer of the clear-binder into either a bigger tank or by direct feed into the hot-mix plant. After use, drums must be disposed, as they cannot be re-used for other purpose. It is usually recognized that up to 3% of the clear-binder may remain stuck to the walls of the drum and is consequently wasted. Besides cost consideration, there is a problem of release of waste in the environment.
Ideally, clear-binders should be user friendly and handled in such a way that there is no need for dedicated facility, limited need for flushing, and easy operation enabling to shift from normal asphalt mix production to clear-binder mixes production, in a short time and with as limited as possible production of waste
The above discussion is not intended as an admission that any of the foregoing is pertinent prior art. All statements and representations are based on the information available to the applicant and do not constitute any admission as to the correctness of the statements and representations or the public availability of the information.